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A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Celestial Navigation Data from USNO--alternative
From: Bill Ritchie
Date: 2019 Nov 30, 15:23 -0800
From: Bill Ritchie
Date: 2019 Nov 30, 15:23 -0800
Frank, Thank you for all the helpful information re Delta T.
You asked for the values of ΔT that, after rounding to 1 place of decimals, give USNO quoted values for the MOON on 2030 OCT 22 at 16:45:30 UT. DR. N41° 29.0' W071° 24.5'. I think the value used must lie between 79 seconds and 86 seconds.
GHA: Quoted 127° 29.2’. ΔT 75” gives 127° 29.25’. ΔT 86” gives 127° 29.15’. So ΔT between 75” and 86”.
Dec: Quoted N4° 48.3’. ΔT 79” gives N4° 48.35’. ΔT 86” gives N4° 48.33’. So ΔT now between 79” and 86”.
Hc: Quoted 28° 10.2’. ΔT 79” gives 28° 10.21’. ΔT 86” gives 28° 10.24’. ΔT confirmed between 79” and 86”.
Zn: Quoted 249.7°. ΔT 79” gives 249.72°. ΔT 86” gives 249.72°. ΔT confirmed between 79” and 86”.
Bill Ritchie 50N 003W
